Liquid cooled heat sink

ABSTRACT

A liquid cooled heat sink includes: a casing having a liquid inlet and a liquid outlet; and a fin unit provided in the casing and having a wave-like structure of a multi-fold sheet that defines a plurality of fluid paths which are aligned in series in a transverse direction relative to the fluid paths. The liquid inlet of the casing is in fluid communication with the liquid outlet of the casing through the fluid paths.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a liquid cooled heat sink, more particularly to a liquid cooled heat sink including a fin unit having a wave-like structure of a multi-fold sheet.

2. Description of the Related Art

As shown in FIGS. 1, 2 and 3, a conventional liquid cooled heat sink 1 generally includes a base 11 made from an aluminum alloy extrudate, a cover 12 for covering the base 11, a pair of parallel side partition plates 13, and a middle partition plate 14 disposed between the base 11 and the cover 12. The base 11 includes a bottom wall 111, a plurality of first and second side partition walls 112 extending uprightly from the bottom wall 111, a plurality of middle partition walls 113 extending uprightly from the bottom wall 111 and disposed between the first and second side partition walls 112, and an attaching protrusion 114 extending from the bottom wall 111 for attaching to an electronic component 15 (see FIG. 2). The area of the bottom wall 111 is larger than that of the attaching protrusion 114 for increasing the heat dissipating area. The length of each of the side partition walls 112 is shorter than that of the middle partition walls 113. The side partition walls 112 have respectively rear edges that are aligned with rear edges of the middle partition walls 113 and that are spaced apart from a rear edge of the bottom wall 111. The side partition walls 112 further have front edges that are disposed farther from a front edge of the bottom wall 111 than front edges of the middle partition walls 113.

The cover 12 is also made from an aluminum alloy extrudate, and includes a top wall 121, a surrounding wall 122 extending downwardly from a periphery of the top wall 121, and a flange wall 123 extending outwardly and transversely from the surrounding wall 122. The top wall 121 is formed with a pair of through-holes 124. A pair of conduits 16 extend respectively from peripheries of the through-holes 124.

The side and middle partition plates 13, 14 are also made from an aluminum alloy extrudate, and are secured to the base 11 and the cover 12. Each of the side partition plates 13 is disposed between an adjacent one of the first side partition walls 112 and an adjacent one of the middle partition walls 113, and has a front edge connected to the cover 12. The middle partition plate 14 is disposed at a middle position in the middle partition walls 113, and has a rear edge connected to the cover 12. In such a manner, a torturous fluid path 17 interconnecting the through-holes 124 is formed.

When the conventional heat sink 1 is in use, heat generated by the electronic component 15 is conducted to the base 11, and is then carried by the coolant along the fluid path 17 in directions as indicated by the arrow shown in FIG. 3.

With reference to FIG. 4, manufacturing of the conventional heat sink 1 is described as below:

(1) The bottom wall 111, the side partition walls 112, the middle partition walls 113, and the attaching protrusion 114 are integrally formed by extruding an aluminum alloy material.

(2) Each of the side and middle partition walls 112, 113 is cut so as to have a desired length.

(3) The attaching protrusion 114 is cut so as to have a desired size that is suitable for attaching to the electronic component 15.

(4) The side and middle partition plates 13, 14 are soldered to the bottom wall 111.

Since the base 11 is made from an aluminum alloy extrudate, each of the side and middle partition walls 112, 113 is relatively thick. As a consequence, the overall contact area between the side and middle partition walls 112, 113 and the coolant is limited, thereby limiting the heat dissipating efficiency of the conventional heat sink 1.

SUMMARY OF THE INVENTION

Therefore, the object of the present invention is to provide a liquid cooled heat sink that can overcome the aforesaid disadvantage associated with the prior art.

Accordingly, a liquid cooled heat sink of the present invention is adapted to be attached to an electronic component and comprises: a casing having a liquid inlet and a liquid outlet; and a fin unit provided in the casing and having a wave-like structure of a multi-fold sheet that defines a plurality of fluid paths which are aligned in series in a transverse direction relative to the fluid paths. The liquid inlet of the casing is in fluid communication with the liquid outlet of the casing through the fluid paths.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which:

FIG. 1 is an exploded perspective view of a conventional liquid cooled heat sink;

FIG. 2 is a schematic sectional side view of the conventional liquid cooled heat sink;

FIG. 3 is a schematic sectional top view of the conventional liquid cooled heat sink;

FIGS. 4A to 4D are perspective views to illustrate consecutive steps for manufacturing the conventional liquid cooled heat sink;

FIG. 5 is an exploded perspective view of the first preferred embodiment of a liquid cooled heat sink according to the present invention;

FIG. 6 is a sectional side view of the first preferred embodiment;

FIG. 7 is a sectional top view of the first preferred embodiment;

FIGS. 8A to 8D are perspective views to illustrate consecutive steps for manufacturing the first preferred embodiment;

FIG. 9 is an exploded perspective view of the second preferred embodiment of a liquid cooled heat sink according to the present invention; and

FIG. 10 is a sectional top view of the third preferred embodiment of a liquid cooled heat sink according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before the present invention is described in greater detail with reference to the accompanying preferred embodiments, it should be noted herein that like elements are denoted by the same reference numerals throughout the disclosure.

Referring to FIGS. 5 to 7, the first preferred embodiment of a liquid cooled heat sink according to the present invention is shown to be attached to an electronic component 5 for absorbing heat generated by the electronic component 5.

The liquid cooled heat sink includes: a casing having a liquid inlet 421 and a liquid outlet 422; and at least one fin unit 3 provided in the casing and having a wave-like structure of a multi-fold sheet 3′ that defines a plurality of fluid paths 30 which are aligned in series in a transverse direction relative to the fluid paths 30. The liquid inlet 421 of the casing is in fluid communication with the liquid outlet 422 of the casing through the fluid paths 30. In this embodiment, two of the fin units 3 are provided in the casing.

Each of the fluid paths 30 is defined by a path-defining wall 31 that is generally U-shaped and that has two opposite straight wall portions 313 and a folded portion 315 interconnecting the straight wall portions 313. Moreover, each of the straight wall portions 313 of the path-defining wall 31 of each of the fluid paths 30 is formed with a plurality of slits 311 so as to permit fluid communication between each two adjacent ones of the fluid paths.30.

The casing has a base 2 that is formed with an attaching protrusion 24 adapted to be attached to the electronic component 5 for absorbing heat from the electronic component 5.

In this embodiment, the casing is made from an aluminum alloy extrudate, and the fin units 3 are mounted in the casing. Note that the fin units 3 can be fixed to (e.g., by welding techniques) or detachably secured to the casing.

The base 2 includes a bottom wall 21, a pair of side walls 22 extending uprightly and respectively from lateral edges of the bottom wall 21, and a partition wall 23 extending uprightly from the bottom wall 21, disposed between and parallel to the side walls 22, and dividing a space between the side walls 22 into two chambers 25. The fin units 3 are respectively disposed in the chambers 25. The partition wall 23 has a rear edge spaced apart from a rear edge of the bottom wall 21. In practice, a plurality of the partition walls 23 can be employed.

In this embodiment, the multi-fold sheet 3′ of each fin unit 3 is made from an aluminum alloy foil.

The casing further includes a cover 4 of aluminum alloy that covers the base 2 and that is connected to an external cooling device (not shown). The cover 4 includes a top wall 41 disposed opposite to the bottom wall 21 of the base 2, and a pair of lateral walls 42 extending downwardly from opposite lateral edges of the top wall 21 to connect with the bottom wall 21 and the side walls 22. The liquid inlet 421 and the liquid outlet 422 of the casing are formed in one of the lateral walls 42 and are provided with inlet and outlet conduits 61, 62 for connecting to the external cooling device. The partition wall 23 is connected to said one of the lateral walls 42 of the cover 4 so as to form the chambers 25 into a tortuous fluid path. Alternatively, the liquid inlet 421 and the liquid outlet 422 of the casing can be formed on the top wall 41 of the cover 4.

In use, the attaching protrusion 24 is attached to the electronic component 5 so that heat generated by the electronic component 5 is conducted to the bottom wall 21 of the base 2 and the fin units 3, and is then carried by the coolant along the fluid paths 30 in directions as indicated by the arrow signs in FIG. 7 to be transferred to the external cooling device for heat dissipation. It should be noted that the structure of the heat sink of this invention can be varied based on actual requirements, such as a horizontal or vertical position relative to the electronic component 5.

With reference to FIG. 8, manufacturing of the heat sink is described as below:

(1) The base 2, which includes the bottom wall 21, the side walls 22, the partition wall 23, and the attaching protrusion 24, is extruded from an aluminum alloy material.

(2) The middle partition wall 23 is cut into a desired length.

(3) The attaching protrusion 24 is then cut into a desired size.

(4) Each fin unit 3 folded and punched from an aluminum alloy foil is disposed in the respective chamber 25 and is soldered to the bottom wall 21.

As shown in FIG. 9, the second preferred embodiment of this invention differs from the previous embodiment in that: since the heat sink has a much smaller size, the partition wall 23 is dispensed with and only one chamber 25 is formed in the casing. In this embodiment, the inlet and outlet conduits 61, 62 of the casing are respectively formed in the lateral walls 42 of the cover 4.

As shown in FIG. 10, the third preferred embodiment of this invention differs from the previous embodiments in that: the partition wall 23 is disposed on the bottom wall 21 such that the width of one of the chambers 25 in the transverse direction transverse to the fluid paths 30 is wider than that of the other. The liquid inlet 421 of the casing is in fluid communication with said one of the chambers 25 having the larger width, and the liquid outlet 422 of the casing is in fluid communication with the other of the chambers 25. As such, the pressure drop of the fluid flow between the liquid inlet 421 and the liquid outlet 422 can be reduced.

With the inclusion of the fin unit(s) 3 in the heat sink of this invention, the aforesaid drawback associated with the prior art can be eliminated.

While the present invention has been described in connection with what are considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements. 

1. A liquid cooled heat sink adapted to be attached to an electronic component, said liquid cooled heat sink comprising: a casing having a liquid inlet and a liquid outlet; and a fin unit provided in said casing and having a wave-like structure of a multi-fold sheet that defines a plurality of fluid paths which are aligned in series in a transverse direction relative to said fluid paths; wherein said liquid inlet of said casing is in fluid communication with said liquid outlet of said casing through said fluid paths.
 2. The liquid cooled heat sink as claimed in claim 1, wherein each of said fluid paths is defined by a path-defining wall that is generally U-shaped and that has two opposite straight wall portions and a folded portion interconnecting said straight wall portions, each of said straight wall portions of said path-defining wall of each of said fluid paths being formed with a plurality of slits so as to permit fluid communication between each two adjacent ones of said fluid paths.
 3. The liquid cooled heat sink as claimed in claim 1, wherein said casing has a base that is formed with an attaching protrusion adapted to be attached to the electronic component.
 4. The liquid cooled heat sink as claimed in claim 1, wherein said casing is made from an aluminum alloy extrudate.
 5. The liquid cooled heat sink as claimed in claim 1, wherein said fin unit is detachably mounted in said casing. 